Simulation training to improve 911 dispatcher identification of cardiac arrest Every day, 9-1-1 dispatchers make front-line acute patient care safety decisions, resulting in life or death outcomes. For example, in the critical first few minuts following a cardiac arrest 9-1-1 dispatchers have been trained to provide instructions to bystanders over the phone. Telephone- assisted CPR (T-CPR) has significantly increased survival from cardiac arrest. However, dispatchers do not recognize approximately 30% of cardiac arrest cases, and as a result, many patients pass away who might have been resuscitated. Given the current low survival rates for cardiac arrest in most communities, increasing T-CPR could have an enormous impact nationwide. Identifying cardiac arrest over the phone is challenging. There is no physical patient, only a voice (often a hysterical one at that). There is no medical record. Callers may be relaying information second-hand. Callers may not speak English well. The primary cardiac arrest screening question asked of all callers to 9-1-1 (Is the patient breathing?) is often answered affirmatively by callers because of the presence of agonal respirations. Although research has found that the frequency with which dispatchers handle cardiac arrests calls is associated with quicker recognition of cardiac arrest (and significantly improved patient survival rates), in general dispatchers encounter only a handful of cardiac arrest calls a year. We propose to increase this vital experience through simulated phone calls for dispatchers at 9-1-1 call centers for a study period of one year. The use of phone-based simulations to improve patient safety has not received a great deal of attention in the literature even though many phone-based emergency systems have a very direct impact on patient care and health outcomes. .We propose a randomized controlled trial to test processes and outcomes of the use of simulated cardiac arrest calls on: 9-1-1 dispatchers' ability to identify cardiac arrests during simulations and in actual calls Secondary aims are to evaluate 1) a dose-response effect of frequency of participation in the simulations for skill acquisition and performance levels , 2) the impact of presence or absence of immediate feedback on performance levels, and 3) the impact of participation in the simulations on provision of T-CRP. To be able to conduct this study as well as disseminate the findings nationwide, we will partner with Emergency Medical Services division of Public Health Seattle-King County, and several call centers in the Pacific Northwest.